1. Field of the Invention
The present invention generally relates to a method of attaching an electronic component, and an electronic component attaching tool.
Specifically, the present invention relates to a method of attaching an electronic component such as a semiconductor device (whose representative is an LSI) and a ceramic condenser to an attachment object such as an IC socket while the position of the electronic component is aligned to the attachment object, and relates to an electronic component attaching tool used in this method.
2. Description of the Related Art
Recently, an electronic device having installed electronic components, and mainly a portable device such as a portable terminal, a cellular phone, and a digital still camera have rapidly become smaller and lighter.
Accompanying this fact, electronic components (whose representative is a semiconductor device) that are installing components for such a downsized electronic device are greatly demanded to be smaller and lighter.
For this demand, a semiconductor device having a package form (referred to as Chip Size Package CSP has been rapidly introduced. The package size of the semiconductor device is made to be near the chip size. The representatives of the CSP are Fine-pitch Ball Grid Array FBGA, Fine-pitch Land Grid Array FLGA, and so on.
Such a semiconductor device is made to be downsized, so that an external terminal of the semiconductor device is also made to have a minute size. Accordingly, when testing is performed on the semiconductor device, when the semiconductor device is attached on a tray or the like, or when the semiconductor device is attached on a substrate or the like, the semiconductor device is aligned with high accuracy to the attachment object such as an IC socket, an IC tray, and an attachment substrate to which the semiconductor device is attached.
Before the CSP was realized, a Small Out-line J-Leaded Package SOJ, a Thin Small Out-line Package TSOP and the like were generally used as the package form of the downsized semiconductor device. Even when the chip size of the semiconductor chip that was attached in the package was changed, the external shape of the package that encloses the semiconductor device was set to the same, that is, not changed. For this reason, the largest size of the semiconductor devices to be attached in the package was used as a standard when the package was designed. Accordingly, the external shape of the semiconductor device package was conventionally larger than the size of the semiconductor device attached in the package.
On the other hand, the semiconductor device needs to be attached at the predetermined position on the attachment object such as the IC socket, the tray, and the attachment substrate with high accuracy. According to Japanese Laid-Open Patent Application No. 10-97887, the attachment object has a position alignment structure for positioning the semiconductor device at a predetermined position.
This position alignment structure uses the external shape of the semiconductor devices (electronic components) to be generally attached in the package form. The position alignment using the external shape of the electronic components was applied in order to simplify the position alignment structure, facilitate the position alignment, and improve the accuracy of the position alignment.
Conventionally, the packages of the semiconductor devices have the common external shape, so that one position alignment structure suitable for the common package external shape can cope with various semiconductor devices.
However, in the case of the CSP whose size is made to be near the smaller chip size, when the chip size is changed, the package size is inevitably changed. Furthermore. in the case of a memory device, the chip size shrinks every about six months even for the same type memory device. Accompanying this chip size change, the package size of the memory device is also changed.
Accordingly, one position alignment structure of the attachment object such as the IC socket, the tray, and the attachment substrate no longer can cope with the downsized devices. For this reason, position alignment structures that correspond to package sizes of the respective CSPs were developed and manufactured so as to be incorporated in the attachment object each time the package size is changed.
FIGS. 1 through 3 show how the conventionally used attachment object copes with the change in the electronic component size. In FIGS. 1 through 3, the CPSs are shown as an example of an electronic component.
For example, it is assumed that before the chip size is changed, a semiconductor chip 2A is cut out from a wafer 1A, and the semiconductor chip 2A is packaged to form a semiconductor device 3A (CSP). As shown in FIG. 2A, the side length of the semiconductor device 3A is “A”, and the pitch of bumps 4 of the semiconductor device 3A is “a”.
The thus-manufactured semiconductor device 3A is attached to the attachment object at the time of the testing, the shipment, the substrate attachment, and the like. FIG. 1 shows the state where the semiconductor device 3A is attached to the IC socket 5A as the attachment object for the testing, the state where the semiconductor device 3A is attached to the tray 6A as the attachment object for the shipment, and the state where the semiconductor device 3A is attached to the attachment substrate 8A. FIG. 2B shows the detailed state where the semiconductor device 3A is attached to the IC socket 5A.
When the chip size shrinks, and a semiconductor chip 2B that is smaller than the semiconductor chip 2A is cut out from a wafer 1B, a semiconductor device 3B that is smaller than the semiconductor device 3A is used for enclosing the semiconductor chip 2B. FIGS. 3A and 3B are enlarged views showing the semiconductor devices 3B and 3A. As shown in FIG. 3A, the side length of the semiconductor device is “B” (B<A). The pitch “b” of bumps of the semiconductor device 3B is equal to the pitch of the bumps 4 of the semiconductor device 3A (b=a).
As described above, conventionally, when the package size is changed from the semiconductor device 3A to the semiconductor device 3B, all of the attachment objects were changed to be suitable ones for the semiconductor devices 3B. In other words, the position alignment structures of the IC socket 5A, the tray 6A, the attachment substrate 8A that are the attachment objects are made based on the external shape of the semiconductor device 3A. Accordingly, these attachment objects for the semiconductor device 3A cannot be used for the semiconductor device 3B whose shape is different from the shape of the semiconductor device 3A.
For this reason; conventionally, when the package size is changed from the semiconductor device 3A to the semiconductor device 3B, the IC socket 5A is replaced with an IC socket 5B suitable for the semiconductor device 3B, the tray 6A is replaced with a tray 6B suitable for the semiconductor device 3B, and the attachment substrate 8A is replaced with an attachment substrate 8B suitable for the semiconductor device 3B.
Thus, when the package size is changed, the attachment object, and the position alignment structure of the attachment object need to be entirely changed, resulting in a large cost. Furthermore, a process of changing the position alignment structure requires much time, and the serviceability ratio of the attachment objects are lowered.
In addition, when the package size is changed, and a period for changing and developing the position alignment structure is long, a service period of the developed position alignment structure becomes short because the life cycle of the semiconductor device is short. As a result, an equipment cost generated by the package size change cannot be recovered.